Extreme pressure lubricating oil containing sulfur-chlorinated esters of chlorendic acid



United States Patent EXTREME PRESSURE LUBRICATING OIL (ZON- TAINING'SULFUR-CHLORINATED ESTERS OF CHLORENDIC AClD Amos' Dorinson, Homewood,111., assignor to Sinclair li eglning Company, New York, N'.Y., acorporation '0 ame N0 Drawing. Filed: Aug. 3, 1956, Ser. No. 602 061 5Claims. (Cl. 2 52-4'8.4)

This invention relates to. sulfur-chlorinated esters of chlorendic acid,and particularly to the use of such esters in mineral oils to provideextreme pressure lubricants and metaleworking oils having improvedproperties. This invention further relates to extreme pressurelubricants of improved load carrying ability which satisfy therequirements demanded in the lubrication of bearing, gears, and thelike, subjected to heavy loads per unit area of surface.

The present invention is particularly concerned with cutting oils usedin broaching, gear cutting, hobbing, planing and similar operations inwhich metal is removed from the work piece at a comparatively low rate,e.g. at cutting speeds of to 20 surface feet per minute. The metal chipsremoved vary in. thickness from 0.005 to 0.0005 inch. A major objectiveof cutting operations of this type is the achievement of a good surfacefinish, and, therefore, one of the functions of a cutting oil used insuch operations is to improve the surface finish obtained.

Certain short-chain chlorinated compounds such as carbon tetrachloride,ethylene dichloride and diisobutylene dichloride are known to beespecially effective as additives for broaching and gear cutting oils.Although an excellent surface finish can be obtained on work pieces bythe inclusion of carbon tetrachloride in broaching and gear cuttingoils, this compound is not suitable as" a-cut-- ting oil additive fortwo reasons. First, due to its volatility carbon tetrachloride israpidly lost by evaporation from the cutting oil during use thusnecessitating close control of the concentration and frequentreplenishment with fresh carbon tetrachloride. Second, carbontetrachloride is a toxic substance which causessevere physiologicaldamage when inhaled as a vapor or when absorbed through the skin bycontact. Ethylene dichloride is also highly volatile. Diisobut'ylenedichloride, which might be used as a. substitute for carbontetrachloride due to its lack of toxicity, is'objectionable because ofits highly on pleasant odor which could not be tolerated for the'lengthof an average working day. Therefore, a need exists for a non-toxic,non-volatile, substantiallyodorless, mineral oil-soluble additive whichimparts extremepressure properies to a cutting oil composition.

In accordance with the present invention Ihave discovered that valuableextreme pressure'additives can be prepared by sulfur-chlorinatingunsaturated esters of chlorendic acid and that the addition of suchadditives to mineral lubricating oils provides extreme pressurelubricating compositions of improved load' carrying ability underconditions of high mechanical loading. As cutting oils or metal workingfluids, mineral oils which contain sulfur-chlorinated esters ofchlorendic acid, are useful in reducing the surface roughness ofmachined parts.

The oil-soluble sulfur-chlorinatedesters added to mineral lubricatingoils in preparing; lubricating compositions of this invention canv beobtained by sulfur-chlorinating, anoil-soluble ester of chlorendic acidof thefollowing formula:

in which R is an unsaturated aliphatic, including cycloaliphatic,hydrocarbon group containing 3 to. 20 carbon atoms and R is hydrogen orthe identical or non-identical member selected from the same group as R.More specifically, the unsaturated members'includ'e alkenyl groups suchas allyl, oleyl, cyclohexenyl and ester groups from unsaturated alcoholsderivedfrom acids such as linoleic', myristoleic, cinnamic, angelicand'the like; which unsaturated members can, if desired, be substitutedas withchlorine for instance. Although the monoesters can be employed,the preferred esters of chlorendic acid are di'-' esters andparticularly those in which the ester groups are mono-olefinic andcontain from 16 to 18 carbon atoms. A preferred diester can be obtainedfrom the un-- saturated alcohols derived from sperm oil The esters canbe prepared by any suitable method as, for example, by reactingchlorendic anhydride with an excess of the appropriate unsaturatedalcohol. The esterification reaction can be carried out in the presenceof a catalyst such as p-toluene sulfonic acid until the theoreticalamount of water has been removed. Alternatively, chlorendic acid maybeused instead of the anhydride and inane method two moies'of water areevolved for each mole of chlorendic diester formed. The water ofreaction may be removed azeotropically by distillation with a solventsuch as benzene or toluene.

The sulfur-chlorination of the chlorendic acid ester is accomplished byreacting each mole of chlorendat'e ester with about .5 to 2 moles of asulfur chloride such as sulfur monochloride or sulfur dichloride at atemperature in the range of about to 300 F. Frequently, the exothermicheat of reaction will maintain the reaction mixture within the desiredtemperature range although in large scale preparations it may benecessary to use ex-- ternal cooling means.

In oil blends which are usedas metal working fluids in operations suchas planing, .broaching, gear cutting and the like, the amount ofadditive employed can depend upon the particular ester in the additive.For esters of high molecular Weight, for example, sulfur-chlorinatedoleyl chlorendate diester, the amount employed will usually be about 9to 35% by weight whereas for the lower molecular Weight esters, such assulfur-chlorinated diallyl chlorendate, the amount used in general willrange from 5 to 30% by weight. The compounding of oils for extremepressure lubricants frequently requires about 0.5 to 10% of thesulfur-chlorinated chlorendate ester. These percentages are based on theweight of the mineral oil present. The manner in which thesulfur-chlorinated es-- esters of chlorendic acid are prepared and'theproper ties of lubricating oils containing the esters are illustrated inthe following examples which are not to be considered as limiting.

EXAMPLE I Preparation of oleyl ch l orendate di ester A mixture of 705grams of chlorendic anhydride and 1000 grams of commercial oleyl alcohol(hydroxyl number 214, iodine number 83) was dissolved in 1000 cc. ofxylene and 10 grams of p-toluene sulfonic acid were added added as acatalyst. The mixture was heated to reflux for 10 hours until 44 cc. ofwater had been col.- lected in a Dean-Start trap attached to theesterificationapparatus. The reaction mixture was then washed once with0.25 N KOH in 1:1 alcohol-water and twice with 1:1 alcohol-water. Afterclarification by filtration, the reaction mixture was freed of xylene bydistillation and the last traces of solventwere removed under vacuum ata pot temperature of 300 F. The reaction product was a dark oily liquidwith the characteristics listed below.

Percent chlorine; 24.0 Acid number 0.28 Saponification number 127.9'Iodine number 50.1

EXAMPLE II Preparation of allyl chlorendate diester A mixture-of 1500grams chlorendic anhydridedissolved in 2000 cc. of allyl alcohol with 10grams of ptoluene sulfonic acid as a catalyst was refluxed for 32 hoursand the excess allyl alcohol was removed by dis;

tillation. The residue was taken up in a mixture of pen-. o

tame and benzene and was washed first with -aqueous KOH and then withwater.- The solvent was distilled off, first at atmospheric pressure andfinally at 2-3 mm. pres sure. The product was a dark viscous liquidhaving the following characteristics.

Percent chlorin I 44.8

Acid number; 0.10

Saponification number 236.8

Iodine number 107.1

EXAMPLE III Sulfur-chlorination of oleyl chlorendate diester A portionof oleyl chlorendate diester containing 22.6% chlorine, with asaponification number of 119.4 and arr-iodine number of 50.0, wasreactedwith sulfur monochloride. To 1541grams of the di-oleylchlorendate, 208 grams of sulfur monochloride were added at 140167 F.and the reaction mixture was stirred for 6 hours at 158 F.. The reactionmixture was then blown with air at 140 F. to purge it of free hydrogenchloride, and the further evolution of hydrogen chloride wasinhibited'by the addition of 0.2% of propylene oxide. The product athick, sticky, dark brown substance at room temperature,- contained5.85% sulfur and 25.8% chlorine. 1

EXAMPLE IV Szilfur-chlofination of allyl chlorendate diester To 600grams of allyl chlorendate diester, 115 grams ii ofsulfur monochloridewere gradually added at a temperature of 195210 F. The reaction mixturethickened progressively and eventually became so viscous that furtherstirring was impossible. This tacky, semi-solid material contained 7.18%sulfur and 44.7% chlorine.

EXAMPLE V w Compounded oils containing sulfur-chlorinated oleylchlorendate diesters Compounded oils were prepared withsulfur-chlorinated (Ii-oleyl chlorendate, as prepared in Example HI, byblending the additive into acid refined Coastal naphthenic oils at 150F. to 210 F. The additive remained .completely dissolved in the oil atroom temperature.

The following blends were made up in mineral oils of differentviscosities.

' Percent Percent Viscosit Blend N o. Additive PercentS O SUS at g 7 100F.

4 EXAMPLE v1 Compounded oils containing sulfur-chlorinated allylchlorendate diester Eighty parts of the sulfur-chlorinated diallylchlorendate of Example IV were mixed with parts of benzene to aid inblending the additive into oil. Seven hundred and. eight-seven grams ofthis mixture were added to i 5025 grams of an acid-refined Coastal oilof'17S seconds viscosity at 100 F. It was found necessary to add 1839grams of benzene to keep the sulfur-chlorinated diallyl chlorendatecompletely dissolved in the oil at room temperature. The final blend,which had'8.25% of sulfurchlorinated diallyl chlorendate incorporatedtherein, contained 0.79% sulfur and 3.28% chlorine; and had a viscosityof 96.6 SUS at F.

EXAMPLE VII Sulfur-chlorinated chlorendate esters as metal-workingadditives The advantages obtained by employing the lubricatingcompositions of the present invention as cutting oils becomeparticularly apparent in cases where the surface finish requirements forthework piece are unusually,

stringent. The effect of oil blends containing sulfurchlorinated oleylchlorendate diester as a cutting oil was demonstrated by means of anorthogonally cutting planer operation. As shown below, the various oilblends prepared in accordance with Examples V and VI were rated.

according to the surface roughness of the cut surface as determined by aprofilometric measuring instrument. Results arev shown in Table I below-1 Blends prepared in Example V.

Oil blends containing sulfur-chlorinatedoleyl chlorendate diester weretested for extreme-pressure load carry-. ing ability in the Falexlubricant testing apparatus, Also an oil blend containing 26% by weightof a non-sulfurchlorinated oleyl chlorendate'diester was tested. In thistest an uncompounded mineral oil does not allow the test to run for thethree-minute breakin period at 300 lbs. load without failure. As can, beseen, the sulfurchlorinated diesters provide extreme pressurelubricants.

of improved load carrying ability.

TABLE II Oil Blend Percent Failure Additive Load, Lbs.

2 10 8 4, 500V 4 1 5 3 4, 500 5 l 2 1, 500 7 2s 1, 250

1 Blends prepared as in Example V.

1 26% Oleyl chlorendate in oil.

I Did not fail at load limit of the apparatus.

I claim: I I p p 1. A new composition of matter consisting essentiallyof a mineral lubricating oil and an amount suflicient to increase the,load carrying capacity of the oil'of a sulfurchlorinated oil-solubleester of 'chlorendic acid produced by reacting a sulfur chloride and anoil-soluble chlorendic acid ester in a ratio of'about .5 to 2 moles ofsulfur chloride to 1 mole of said chlorendic' acid ester wherein 1 Blendof Example VI.

5 6 said ester group is an unsaturated aliphatic hydrocarbon ReferencesCited in the file of this patent radical containingi rom 3 to 2 0 carhonatoms. UNITED STATES PATENTS 2. The composition of claim 1 in which theester is about 5 to 35% of the mineral oil. 2,156,265 M11181 May 2, 19393. The composition of claim 1 in which the ester is 5 2,157,873 PesklMay 1939 about (L5 to of the mineral oil et 2 4. The composition ofclaim 2 in which the ester is a 2,387,286 f 1945 diester in which eachester group contains from 16 to 18 2,433,853 LmcPln et a1 1948 carbonatoms NOV. 30, 2,771,423 Dorinson Nov. 20, 1956 5. The composition ofclaim 4 in which the ester is a 10 diester in which eachester groupcontains from 16 to 18 carbon atoms.

1. A NEW COMPOSITION OF MATTER CONSISTING ESSENTIALLY OF A MINERALLUBRICATING OIL AND AN AMOUNT SUFFICIENT TO INCREASE THE LOAD CARRYINGCAPACITY OF THE OIL OF A SULFURCHLORINATED OIL-SOLUBLE ESTER OFCHLORENDIC ACID PRODUCED BY REACTING A SULFUR CHLORIDE AND ANOIL-SOLUBLE CHLORENDIC ACID ESTER IN A RATIO OF ABOUT .5 TO 2 MOLES OFSULFUR CHLORIDE TO 1 MOLE OF SAID CHLORENDIC ACID ESTER WHEREIN SAIDESTER GROUP IS AN UNSATURATED ALIPHATIC HYDROCARBON RADICAL CONTAININGFROM 3 TO 20 CARBON ATOMS.